Electric battery.



un. 7:6,762 Patented nec. 23, |902.

.a. Bossu.

ELECTRC BATTERY.

(Application filed Feb. 20, 1901.. No Model.)

NiTnn STATES GEORGES ROSSET, OF PARIS, FRANCE.

ELECTRIC BATTERY.

SPECIFICATION forming part of Letters Patent No. 716,762, dated December 23, 1902.

Application filed February 20, 1901. Serial llo. 48.169. (No model.)

To all whom it may concern:

' Be it known that I, GEORGES Rossnr, a citizen of the Republic of France, residing in- Paris, France, have invented certain Improvements in Battery-Cells, of which the following is a specification.

This invention relates to cells for generating electric currents; and the object is to provide the cell with a depolarizing agent which has the function of a chemical sponge, absorbing oxygen from the atmosphere and giving it up to the cell to effect depolarization. This depolarizing agent is inexhaustiblefor the reason that it is automatically regenerated by reoxidation in the atmosphere.

In the accompanying drawing the/iigure is a' Vertical axial sectionpf amccll embodying one form of the invention, which will be hereinafter described.

In carrying out my invention I employ as a depolarizing agent a-salt containing cupric acid in chemical combination with a base. The cuprates of the alkalies, and especially cuprate of ammonia, constitute in most cases the basis of my depolarizing agent. The reduction of these salts from the higher oxidation (cuprate) to the lower (coprite) requires less energy than is required by the reduction from the cuprite to the metallic state, (copper,) and in the presence of the oxygen of the atmosphere the products of the decomposition of the cuprate always restore the solution of the cell to the maximum state of oXidation. On the other hand, these cuprates and cuprites are readily obtainable in a state of solution, which state is most favorable to the successive reactions of reduction and reoxidation. In fact, cuprate and coprite of ammonia are soluble in pure water or in water containing a small proportion of ammonia. The cuprates and cuprites of potassium and sodium are soluble in water in the presence of certain organic substances, such as tartaric acid, glycerin, dre. The cuprite itself has also an oxidizing action and if necessary may depolarize the negative-pole electrode of a cell, depositing thereon metallic copper, and during the succeeding periodlof rest this copper is redissolved and produces rst coprite and then cuprate, as will be understood from the reaction hereinafter described. In order to avoid diifusion of the polarizing agent, I employ a porous vessel consisting, essentially, of a colloidal membrane. One way in practice consists in taking a porous vessel of any kind and precipitating or depositing in the substance of the Walls of such vessel an insoluble or only slightly-soluble compound, such as ferrocyanid of copper. For this purpose ordinary porous vessels lled With the depolarizing solution are 4immersed (for about forty-eight hours) in a trough containing a rather weak solution of a ferrocyanid of an alkali. By this means ferrocyanid of copper is deposited in the walls of the vessels. There is no need to fear a too-prolonged immersion, because the deposition ceases automatically When the porous vessel allows only pure Water to pass through. It is to be noted that the porous vessel may be prepared in the pile itself. It is sufficient to add at first to the exciting solution (which of course must not be incompatible therewith) a few cubic centimeters of a solution of a ferrocyanid ofan alkali. Any excess of ferrocyanid is not detrimental. It precipitates the zinc` salt which is formed in the working of the battery, which thus disappears.

The depolarizing agent may be prepared by startingwith any copper salt or With metallic copper. In the first case sulfate of copper, for instance, in concentrated solution, may be precipitated bymeans of a concentrated solution of ammonia .or of a stream of gaseous ammonia and then be redissolved in an excess of ammonia. This is cuprate of ammonia. The procedure is exactly the same when it is desired to produce the cuprates of potassium or of sodium, with the sole diiference that the excess of the alkali intended for the purpose of redissolving the precipitate is added in the presence of an organic substance, such as glycerin or tartar-ic acid. In practice I prefer to employ cuprate of ammonia. is not necessary to wash the-precipitate before redissolving it, because the ammonium sulfate only renders the solution more conductive. In preparing the depolarizing agent from metallic copper it is sufficient to pour or spray ICQ ammonia on Waste pieces (filings, turnings) of copper in contact with the atmosphere. Cuprate of ammonia forms and is gradually dissolved. The depolarizing agent may also be prepared in the pile itself by placing copper turnings with ammonia around the positive-pole electrode.

In carrying out my invention a semipervi ous membrane or diaphragm is formed in the walls of the porous Vessel by precipitating ferrocyanid of copper therein in the manner hereinbefore described, the said membrane or diaphragm being maintained in the semipervious colloidal state by reason of this deposition of ferrocyanid of copper and of the solution of cuprate of ammonia. A plate of carbon which forms the positive-pole electrode is placed in the porous vessel, which is filled with a concentrated solution of cuprate of ammonia. A rod or piece of zinc, amalgamated or not, is placed in the outer vessel to form the negative-pole electrode.

In the accompanying drawing, which illustrates a cell embodying my invention, a is a porous Vessel in which is formed a semipervious membrane or diaphragm b by the precipitation of ferrocyanid of copper.

c is the carbon electrode.

d is the exterior vessel.

e is the zinc electrode, which may be amalgamated.

The upper edges of the vessels are carefully coated with paraffin f. The inner vessel is represented as closed at the top andthe closing-piece g provided with apertures hfor the passage of the zinc c and for the escape of gases. This closing-piece may be of paraffin.

The exciting solution or liquid will be preferably composed of a concentrated solution of sal-ammoniac in the proportion of two huni dred to two hundred and fifty grams to one liter of water.

The eleotromotive force of one cell of this battery with amalgamated zinc, sal-ammoniac solution, cuprate of ammonia, and carbon is about 1.2 volts on an open circuit.

The following are the reactions which may be assumed to take place in this battery: The zinc dissolves at the negative-pole electrode and produces products which vary according to the nature of the exciting liquid employed. Polarizing hydrogen appears on the carbon at the positive-pole electrode, and being in the presence of cuprate, which has a strong oxidizing action, it reduces the latter to the condition of cuprite, but stops at this stage, because the reduction of cuprate to cuprite requires less work than the reduc- The diusion currents, aided by the lightness of the freed ammonia, bring this cuprite to the surface of the cell-#that is to say,`to the atmosphere- Whose oxygen converts the cuprite back into cuprate, which being denser` In the case of an intense current (produced, for example, by a prolonged short circuit) the cuprite would no't have time topass away, and would have a depolarizing effect by depositing copper, which is a Very good conductor, on the carbon.

/ONH3 -l-H2O ONH3 ONH ONH 3=12Cu/ 3 \oNH3 -\oNH, and this cuprite of ammonium in the atmos- 20ml-20u f phere, and in the presence of the requisite quantity of ammonia which has just been freed by previous reaction, would be converted back into cuprate in accordance With the first reactions described. In fact no metallic copper is ever found in a permanent condition on the carbon, and the solution never loses its color in the atmosphere, so rapid is'the reoxidation to cuprate. The inexhaustibility of the depolarizing agent is shown also by experience. It is sufficient to change the zinc and to renew the exciting solution in order to enable the battery to resume its normal output with the same resistance. It may at most be advisable to make up from time to time for the unavoidable losses of ammonia, and even this is not necessary if chlorid of ammonium, which gives up the exact quantity of ammonia gradually to the depolarizing agent, is used as the exciting solution.

During the operation of the battery the depolarizing agent consists of a mixture of sel IOO

IIO

rilegr'ee taining cupric acid in chemical combination with ammonia as a base.

4. A cell for generating anelectric current, containing a self-generating polarizing agent and havingV a porous vessel in the pores of which is formed a semipermeable membrane of errocyanid of copper Which serves to arrest the passage of the depolarizer by a physico-chemical filtering action, substantially as set forth.

In Witness whereof I have hereunto signed my name, this 8th day of February, 1901, in the presence of two subscribing Witnesses.

GEORGES ROSSET.

Witnesses:

JULES ARMENGAUD, Jeune, J. ALLIsoN BOWEN. 

